I'm not saying the .mp3 files are sample accurate with their respective .wav files. But they aren't totally out of sync as some of you demonstrate.

Images show three tracks:First track is original wav. Second track is .wav mixdown then converted into .mp3 by foobar2000 and that .mp3 is imported back into Studio One. Third track is .mp3 mixdown then imported back into Studio One.

First image shows start of the song. As you can see, first two track are perfectly aligned (with respect to 1ms timeline resolution). Third track is 25 ms delayed.

Second image shows end of the song. First two tracks are still aligned and third one is still 25 ms delayed.

Note: There is nothing wrong with working with .mp3 files. At least Cubase users talk to me this way (in truth, they are much more specific:"Buy to yourself respectable DAW which works"), and there is many such users around me (in fact everybody, becase I'm only one with different DAW). In other words, everybody around me works with .mp3 files just fine.

Note2: Of course nobody will send mp3 files to mixing engineer, but they are good enough for composing phase (but not in Studio One).